body {
  font-size: 14px;
  margin: 0;
  box-sizing: border-box;
}
.sidebar {
  display: inline-block;
  width: 20%;
  box-sizing: border-box;
  vertical-align: top;
}
.sidebar ul{

  list-style: none;
}
.sidebar li{
  cursor: pointer;
  height: 30px;
}
.sidebar li.selected{
  background-color: greenyellow;
  
}
.content {
  display: inline-block;
  width: 40%;
  padding: 5px;
  box-sizing: border-box;
}
.content textarea {
  width: 100%;
}
.preview {
  display: inline-block;
  width: 38%;
  height: 100%;
  padding: 5px;
  box-sizing: border-box;
  vertical-align: top;
}
.alter{

  margin-left: 10px;
}

img{

  width: 100%;
  height:100%;
}
.b1,.b2{
  background-color: greenyellow;
  width: 35px;
  height: 35px;
}
